Handsome and thoughtful ... The new Terminal 2 at Heathrow airport, designed by Norman Foster. Photograph: BAA press

The first artists' impressions of Heathrow's new Terminal 2 are just as you would expect, and even hope, them to be. Here is Norman Foster and his mighty architectural practice at its best: a sequence of crisp, elegant, uncluttered spaces set under a single swooping, aerofoil-like roof, awash with daylight from 10-metre-high north-facing windows, as free as technically possible from the murky glow of artificial lighting. Handsome, thoughtful, and making the most of leading-edge technologies, it all adds up to an airport terminal that will easily rank among the world's best.

Heathrow might often be seen as a nightmare of maze-like design punctuated with stained carpets, low ceilings, tangles of wires and general low-grade tat – yet Foster, an architect in love with aerospace, promises a wholly new experience for passengers hacking their way through the airport's existing terminals.

The work won't be complete until 2019, but for those jetting in and out of Heathrow a decade from now, the airport will be a very different place. Terminals 3 and 4 will have been upgraded, Richard Rogers's bravura Terminal 5 will have been extended with a satellite building, and there might even be a third runway in place.

That Foster can make a difference is evident from the two superb airports he and his team of architects, engineers and contractors have designed and built in China. Hong Kong's Chek Lap Kok airport, opened in 1998, is a marvel of modern engineering. Architecture and infrastructure – trains, buses, aircraft and every conceivable form of airport machinery – have been woven into a seamless whole. The elegant, lightweight structure, or carapace, of the terminal evokes the idea, and even the sense, of flight. It all hangs together so well that this is very often cited as the long-distance travellers' favourite place to change planes.

As for the new terminal at Beijing airport, opened in time for last year's Olympic Games, it is almost overwhelmingly impressive. Shaped like a great dragon under a single wing-like red roof, it is no less than 1.8 miles long, and ranks among the world's largest single buildings. The most ambitious of all airport buildings to date, Beijing's Terminal 3 is a prominent symbol of China's rise as a global superpower, an architectural dragon awakened to a 21st century of mass air travel.

Architects like Foster and Rogers continue to try to make the best out of an increasingly tricky task, both technically, politically and environmentally: how to civilise airport design and, even, how to bring back something of the romance of flight, an ideal captured hauntingly in the final scene of Casablanca, starring Ingrid Bergman and Humphrey Bogart. The days of piston-engine airliners and airfields, where the only necessary architecture was a collection of tents, or at most a cocktail-era, art deco terminal, may be over; but even on a huge scale it must be possible to balance aesthetics with practicality?

There have been some very beautiful air terminals built in the jet age, and none more exquisite than Eero Saarinen's TWA terminal, opened in 1962, at what is now John F Kennedy international airport. Here is a folding, and enfolding, of concrete wings sheltering some of the most voluptuous and compelling spaces ever seen in an airport. But, all too soon, Saarinen's terminal was too small, and unsuitable for mass air travel: today's international terminals need to be vast processing machines, coping with improbable numbers of people wanting to zap around the world as quickly and cheaply as possible.

Of course, you will find slightly more civilised modern airports in less crowded countries than Britain – Oslo airport was a revelation on my recent trip to Norway: all soft light, timber, immaculate lavatories. There are a few inspiring airports around the world that take their cues from local cultures and architectural traditions. The terminal Rafael Moneo designed at Seville airport, and opened in 1991, takes its design from Andalucian mosques, palaces and orange groves. The deep blue vaults of the terminal are gentle and peaceful, two words rarely associated with airports. They also serve to keep the fierce Iberian sun at bay.

The Hajj terminal at King Abdulaziz international airport, Jeddah, designed by the US practice SOM, and completed in 1981, takes the form of what looks like rows of giant white tents. Symbolically, this works well – the terminal was built to serve the crowds flying to Jeddah for the annual Muslim pilgrimage to nearby Mecca – while the design is highly practical, too.

Generally, most of the best new airports are like giant hangars housed under aerofoil roofs. This makes sense for both practical and aesthetic purposes: aircraft and hangars go together like ships and docks, or cars and garages. Meanwhile, these big spaces offer architects the maximum opportunity to design for an endless stream of passengers, while the roofs are configured for modulating flows of daylight into vast interiors – too many older airport buildings remain horribly claustrophobic.

The look of the best of these new global-style airport terminals, however, began with Foster's radical new second terminal at Stansted airport, Essex, opened in 1991. Inside, it might now resemble a third-rate shopping mall, but stripped of the general commercial excess, this would still be the beautiful building it was when completed nearly 20 years ago.

Here, Foster and his team offered passengers a direct walk from train to departure gate, under a beautiful roof in the guise of a hi-tech parasol, with views of the aircraft all the way. I remember following the story of this superb design, and how as it neared completion, Foster and his lead architects were increasingly frustrated by BAA's demand for more and more shops. It's one of the crunch problems with contemporary airports – they can, and do, make more money from shops than from flights. Very quickly, Stansted's crystal-clear new terminal became more like a cross between an aircraft hangar and a car-boot sale.

For those less keen on the shopping and more concerned with business of flying, smaller regional airports may well be the answer. London's City airport, for example, remains a haven for those who like the experience of flight to be as simple, and enjoyable, as possible. The wealthy, meanwhile, can opt for truly elegant modern airfields like Farnborough in Hampshire, from which to soar into the sky in handsomely-appointed executive jets.

Ultimately, however, when most of us are saying we want to fly halfway round the world for the price of a tin of beans, we very much need architects like Foster to make the best of buildings that are as controversial as they are challenging. Whatever happens to cheap, mass flight in the future, at the very least Heathrow airport will be a more civilised a place to cope with in 10 years' time.